While Wild 2 showed a great majority of vacuoles containing only SAG1-positive parasites, Wild 4 showed a significant amount of spontaneous cystogenesis in vitro, and after 48 h and 72 h of infection 54.1% and 66.1% of vacuoles were, respectively, positives for only DBA (an indicative of cystogenesis). This evidence concerns the gene RPS19 and infection.